And I'm Audie Cornish. The U.S. Senate has approved the nation's new top spy. Senators confirmed John Brennan as director of the Central Intelligence Agency, and the whole process has been pretty dramatic. It began last year with the scandalous resignation of Brennan's predecessor, General David Petraeus. And it wound up today after a showy challenge to the vote on the Senate floor. Kentucky Senator Rand Paul filibustered for nearly 13 hours yesterday and into this morning.

In the end, though, the vote wasn't even close. Brennan was approved 63 to 34. And we're joined now by NPR's Tamara Keith. And, Tamara, for those of us who were not up watching C-SPAN in the wee hours, how did that filibuster finally end?

TAMARA KEITH, BYLINE: So the whole filibuster was pretty dramatic, but it ended without much of a flourish. It was a little bit before 1:00 in the morning, and the senator said he had discovered the limits of the filibuster. He said he was in pain - he had worn uncomfortable shoes, it turns out - and he seemed to imply that he had to go to the bathroom. And that's when the talking filibuster ended.

But for most of the day today, there was a question of whether he or another Republican would use the more modern iteration of the filibuster and try to delay or block the vote. And if they had, the vote might not have happened until Saturday or Sunday. But then Attorney General Eric Holder sent a letter over to the senator and that essentially ended the fight.

CORNISH: And, of course, this was in response to concerns the senator had raised about domestic use of drones to kill American citizens. What did the letter say?

KEITH: It was very short. It said: It has come to my attention that you have now asked an additional question. And then I'll let White House spokesman Jay Carney pick up the rest.

JAY CARNEY: Here is from the letter, quote, "Does the president have the authority to use a weaponized drone to kill an American not engaged in combat on American soil? The answer is no. The answer to that question is no."

CORNISH: Senator Paul could've taken this letter as an insult because it was pretty curt, but it seems it was enough for Senator Paul.

SENATOR RAND PAUL: So it has taken a while, but we got an explicit answer. I'm pleased that we did. And to me, I think the entire battle was worthwhile.

CORNISH: And in the meantime, Senator Paul became a Twitter sensation. The hashtag stand with Rand was trending. But in the light of day, what's been the reaction?

KEITH: Yeah, there's been a lot of respect for his use of the talking filibuster, which is pretty rare these days. And the National Republican Senatorial Committee has been fundraising around it. But other people, including Arizona Senator John McCain, said that this was more of a rant. And he took to the floor to criticize Senator Paul's whole premise.

SENATOR JOHN MCCAIN: I've watched some of that quote, "debate," unquote yesterday. I saw colleagues of mine who know better come to the floor and voice this same concern, which is totally unfounded.

KEITH: There are real questions and concerns that Senator McCain nodded to about the use of drones globally and the administration's policy on enemy combatants. But that wasn't what Senator Paul was asking about. Interestingly, three Democrats voted against Brennan's confirmation, but several Republicans voted for him. And that more than made up the difference.

CORNISH: And lastly, Tamara, what does this mean now for John Brennan and the CIA?

KEITH: Brennan is a 25-year veteran of the CIA and has been a close adviser to the president since he took office. He's taking over after retired General David Petraeus left the job abruptly five months ago, admitting an affair with his biographer. And this means that the agency will be led by one of their own. And I think there's hope that he brings stability.